1. Field of the Invention
This invention relates to a device for ensuring the protection against atmospheric agents of electronic or similar apparatuses, in particular high-reliability apparatuses when installed in zones having difficult climatic conditions and in positions difficult to be joined and to be supplied with conventional energy.
In the field of electronic apparatuses the prevailing trend is to reduce consumption and increase reliability, in particular for the purpose of reducing maintenance costs.
These two features must be considered as essential when such apparatuses operate in climatically difficult zones as well as in places difficult to be reached, devoid of conventional energy sources without the possibility of human supervision. The continuous improvement of the above-mentioned features has introduced the problem of effectively protecting the apparatuses not only against atmospheric agents, but also against extremely high or low environmental temperatures.
2. Description of the Prior Art
For the protection of these electronic apparatuses so-called "shelter" devices are normally used essentially in the form of box-like structures wherein these apparatuses are housed.
The known shelters always offer a protection against inclement weather and sometimes also provide a certain thermal insulation due to the thermal insulating material of their walls.
However, the power dissipated by the electronic apparatuses within such known shelters results in a positive temperature difference between the inner and outer wall surfaces, but the inner temperature always follows the daily and seasonal environmental temperature variations. This means that inside the shelter maximum and minimum temperature peaks about equal to those of the environmental temperature plus such temperature difference can be detected.
Accordingly, these known shelters are effective only if the maximum and/or minimum environmental temperature peaks, plus such difference, result in inside maximum and/or minimum temperature peaks which are compatible with a perfect operation of the apparatuses.
If the outside maximum and/or minimum temperature peaks do not satisfy the above condition, other solutions must be found. When the shelters must operate in zones wherein the maximum inside temperature peak, calculated as hereinabove, is greater than the allowable temperature, it is possible to provide shelters with automatically or manually controllable openings, in order to reduce the inside temperature to values corresponding to outside temperature. However this solution, which is effective only when the outside temperature is compatible with the operation of the apparatus, shows different drawbacks, as for example a reduced protection against inclement weather when the shelter is open, a poor reliability when the shelter opening is automatically controlled, or high costs in case of a manual shelter opening control.
Another solution is to provide shelters having air conditioners, heat pumps or other cooling or heating means.
However this solution requires a considerable energy consumption for producing heat in or subtracting heat from the shelter, and involves the use of plants of low reliability.